Going on a huge shopping spree? If you want to be the most successful, this is how you should dress.
Wear a grey tank top. If you're going to try on a white shirt, a grey tank top is actually better than a white one.
When going to try stuff on, wear a t-shirt that you can change easily.
Same as the step above, wear comfy shorts (But make sure they aren't ugly. You want to know how the shirt looks with shorts you'll actually wear.)
Wear a bra with flexible straps. If you have a bra that has convertible straps, that'll let you try on many different kinds of shirts while getting to see what they look like without the straps showing. Otherwise, just wear a strapless bra.
Don't wear earrings. They will just bug you to death!
Shoes. Most likely you should wear something with socks that you can walk around in for a while. Flip flops are also easy to take off so it just depends where you're going and for how long.
And lastly your hair. Just wear your hair however you wear it the most.
Put your phone in your handbag. It will only fall out of your pocket when putting on or taking off clothes. Losing or breaking a cell phone is SO un-fun.
If you have a choice between contacts and glasses, wear contacts. Glasses often get caught on collars and can easily be lost track of or accidentally stepped on in a dressing room.